Trigonometry
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@TinySlayer free cash
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- #6
I don't have time to do it for you, but if you use trigonometric identities, it's fairly straight forward.
Most useful: https://en.wikipedia.org/wiki/Pythagorean_trigonometric_identity#Related_identities
Most general: https://en.wikipedia.org/wiki/List_of_trigonometric_identities
Just treat cos(x) as a single object, then you can just shuffle things around to get the answer once you find the right identity.
Edit:
Here is a view from of someone solving a similar style problem:
Source: https://socratic.org/questions/if-sin-x-0-6-what-is-the-value-of-cos-x
Most useful: https://en.wikipedia.org/wiki/Pythagorean_trigonometric_identity#Related_identities
Most general: https://en.wikipedia.org/wiki/List_of_trigonometric_identities
Just treat cos(x) as a single object, then you can just shuffle things around to get the answer once you find the right identity.
Edit:
Here is a view from of someone solving a similar style problem:
Source: https://socratic.org/questions/if-sin-x-0-6-what-is-the-value-of-cos-x
Last edited:
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- #8
This might be a simpler page if your Ancient Egyptian isn't up to scratch: https://www.purplemath.com/modules/idents.htm
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- #9
Here is someone solving a similar problem, I suggest copying their method: https://socratic.org/questions/if-sin-x-0-6-what-is-the-value-of-cos-x
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D. is 45 degrees, can't remember how to do the rest cause it's been a year since I did any maths like that
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I haven't done this in years but here's what I got.
General equation: sin^2(x) + cos^2(x) = 1
-------
5. if sin(x) = 0.8
(0.8)^2 + cos^2(x) = 1
cos^2(x) = 1 - 0.64 = 0.36
cos(x) = 0.6
6. if cos(x) = 0.6
sin^2(x) + (0.6)^2 = 1
sin^2(x) = 1 - 0.36 = 0.64
sin(x) = 0.8
7. if cos(x) = 0.8
sin^2(x) + (0.8)^2 = 1
sin^2(x) = 1 - 0.64 = 0.36
sin(x) = 0.6
tan(x) = sin(x)/cos(x)
tan(x) = 0.6/0.8
tan(x) = 0.75
8. if sin(x) = 0.5
(0.5)^2 + cos^2(x) = 1
cos^2(x) = 1 - 0.25 = 0.75
cos(x) = 0.86602540378
cot(x) = 1/tan(x) = cos(x)/sin(x)
cot(x) = 0.86602540378/0.5
cot(x) = 1.73205080756
D. tan^-1(1) = 45 deg
tan(x) = sin(x)/cos(x)
for tan(x) == 1, sin(x) must be equal to cos(x)
I can't explain this properly ask Tiny lol.
E. if cot(x) = tan(x)
cot(x) = 1/tan(x)
tan(x) = 1/tan(x)
tan(x) * tan(x) = 1
tan^2(x) = 1
tan(x) = sqrt(1) = 1
tan-1(1) = 45 deg same as D.
General equation: sin^2(x) + cos^2(x) = 1
-------
5. if sin(x) = 0.8
(0.8)^2 + cos^2(x) = 1
cos^2(x) = 1 - 0.64 = 0.36
cos(x) = 0.6
6. if cos(x) = 0.6
sin^2(x) + (0.6)^2 = 1
sin^2(x) = 1 - 0.36 = 0.64
sin(x) = 0.8
7. if cos(x) = 0.8
sin^2(x) + (0.8)^2 = 1
sin^2(x) = 1 - 0.64 = 0.36
sin(x) = 0.6
tan(x) = sin(x)/cos(x)
tan(x) = 0.6/0.8
tan(x) = 0.75
8. if sin(x) = 0.5
(0.5)^2 + cos^2(x) = 1
cos^2(x) = 1 - 0.25 = 0.75
cos(x) = 0.86602540378
cot(x) = 1/tan(x) = cos(x)/sin(x)
cot(x) = 0.86602540378/0.5
cot(x) = 1.73205080756
D. tan^-1(1) = 45 deg
tan(x) = sin(x)/cos(x)
for tan(x) == 1, sin(x) must be equal to cos(x)
I can't explain this properly ask Tiny lol.
E. if cot(x) = tan(x)
cot(x) = 1/tan(x)
tan(x) = 1/tan(x)
tan(x) * tan(x) = 1
tan^2(x) = 1
tan(x) = sqrt(1) = 1
tan-1(1) = 45 deg same as D.
